The government said it hadn’t made a decision yet, and would consider the matter over the next 10 days, but that it was “minded” to inject itself in European Union deliberations over the deal on public-interest grounds.

If the government decides to intervene, it would refer the deal to Britain’s competition authorities and its media watchdog, Ofcom. The proposed transaction is already being reviewed by the commission, Europe’s top competition authority. Brussels’ authority extends only to determining whether the deal poses a threat to European-wide competition.

Karen Bradley,
the U.K. minister responsible for culture, media, and sports, said she had written to the two parties to inform them such an intervention would be based on two concerns: media “plurality,” or ensuring a diversity of ownership among British media, and commitment to broadcasting standards.

Rupert Murdoch
and his family are major shareholders of Fox and
News Corp,
which publishes a number of other British media titles, including the Sun tabloid, the Times of London, and the Sunday Times. Fox and News Corp, which is also the parent company of The Wall Street Journal, were part of the same company until it split in 2013.

An earlier effort by News Corp—before Mr. Murdoch separated the two companies—to buy all of Sky was abandoned amid a public outcry over a phone-hacking scandal at News Corp’s now-closed News of the World.

Fox said that it anticipated “a thorough review” by regulators but it is confident of approval. A spokesman for Sky declined to comment.

The companies formally registered the deal for review with the commission on Friday. The commission has set itself a preliminary deadline of April 7 to examine the deal, though that could still be extended.